This invention relates to the separation of a desired particulate material from a mixture of materials, and more particularly to method and apparatus for analyzing the efficiency of harvesting a particulate food product.
Harvesters for grains and other particulate food products include components which are adjustable in order to achieve maximum efficiency of product recovery. In a grain harvester, for example, such adjustable components include platform reel, shelling cylinder, straw walkers and sieves, air blower, concave to cylinder spacing, and others. These are adjusted selectively while periodically determining the amount of grain returned to the ground with the chaff, straw and other trash.
In the harvesting of grain, for example, it has been the general practice heretofore that kernels trapped with trash either are manually counted on the ground within a given area, or are manually caught up and counted in a basket or other container as they are expelled toward the ground over a given distance of travel of the harvester, and then in either case the count is converted to bushels per acre of grain loss. This laborious and time consuming procedure characteristically requires as much as two days of harvesting to reach optimum adjustment of harvester components to achieve minimum grain loss. By that time it frequently occurs that harvesting has reached a field of different character whereby the procedure must be repeated. In any event, the labor time and intervening loss of grain represent substantial cost factors of production.
A grain monitor has been proposed in which the sounds of grain falling on a sounding board are picked up by a microphone and the resulting electric signals are amplified and applied to a meter to give an indication of a volume of grain being lost. This monitor requires an extensive and costly filtering system for removing unwanted electric signals due to the extraneous noises developed by straw and other debris and by the harvester itself, and the degree of accuracy of indication of quantity of loss per acre is less than desirable.